lustre/llite/dcache.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of Lustre, http://www.lustre.org.
   7  *
   8  *   Lustre is free software; you can redistribute it and/or
   9  *   modify it under the terms of version 2 of the GNU General Public
  10  *   License as published by the Free Software Foundation.
  11  *
  12  *   Lustre is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with Lustre; if not, write to the Free Software
  19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <linux/fs.h>
  23 #include <linux/sched.h>
  24 #include <linux/smp_lock.h>
  25 #include <linux/quotaops.h>
  26
  27 #define DEBUG_SUBSYSTEM S_LLITE
  28
  29 #include <linux/obd_support.h>
  30 #include <linux/lustre_lite.h>
  31 #include <linux/lustre_idl.h>
  32 #include <linux/lustre_dlm.h>
  33
  34 /* should NOT be called with the dcache lock, see fs/dcache.c */
  35 void ll_release(struct dentry *de)
  36 {
  37         ENTRY;
  38         OBD_FREE(de->d_fsdata, sizeof(struct ll_dentry_data));
  39         EXIT;
  40 }
  41
  42 void ll_set_dd(struct dentry *de)
  43 {
  44         ENTRY;
  45         LASSERT(de != NULL);
  46
  47         lock_kernel();
  48
  49         if (de->d_fsdata == NULL) {
  50                 OBD_ALLOC(de->d_fsdata, sizeof(struct ll_dentry_data));
  51                 sema_init(&ll_d2d(de)->lld_it_sem, 1);
  52         }
  53
  54         unlock_kernel();
  55
  56         EXIT;
  57 }
  58
  59 void ll_intent_release(struct dentry *de, struct lookup_intent *it)
  60 {
  61         struct lustre_handle *handle;
  62         ENTRY;
  63
  64         LASSERT(ll_d2d(de) != NULL);
  65
  66         if (it->it_lock_mode) {
  67                 handle = (struct lustre_handle *)it->it_lock_handle;
  68                 ldlm_lock_decref(handle, it->it_lock_mode);
  69
  70                 /* intent_release may be called multiple times, from
  71                    this thread and we don't want to double-decref this
  72                    lock (see bug 494) */
  73                 it->it_lock_mode = 0;
  74         }
  75
  76         if (!de->d_it || it->it_op == IT_RELEASED_MAGIC) {
  77                 EXIT;
  78                 return;
  79         }
  80
  81         if (de->d_it == it)
  82                 LL_GET_INTENT(de, it);
  83         else
  84                 CERROR("STRANGE intent release: %p %p\n", de->d_it, it);
  85
  86         EXIT;
  87 }
  88
  89 extern struct dentry *ll_find_alias(struct inode *, struct dentry *);
  90
  91 static int revalidate2_finish(int flag, struct ptlrpc_request *request,
  92                               struct dentry **de, struct lookup_intent *it,
  93                               int offset, obd_id ino)
  94 {
  95         struct mds_body *body;
  96         struct lov_mds_md *lmm = NULL;
  97         int rc = 0;
  98         ENTRY;
  99
 100         if (!(flag & LL_LOOKUP_NEGATIVE)) {
 101                 body = lustre_msg_buf(request->rq_repmsg, offset);
 102                 if (body->valid & OBD_MD_FLEASIZE)
 103                         lmm = lustre_msg_buf(request->rq_repmsg, offset + 1);
 104                 ll_update_inode((*de)->d_inode, body, lmm);
 105                 mdc_lock_set_inode((struct lustre_handle *)it->it_lock_handle,
 106                                    (*de)->d_inode);
 107         } else
 108                 rc = -ENOENT;
 109
 110         ptlrpc_req_finished(request);
 111         RETURN(rc);
 112 }
 113
 114 int ll_have_md_lock(struct dentry *de)
 115 {
 116         struct ll_sb_info *sbi = ll_s2sbi(de->d_sb);
 117         struct lustre_handle lockh;
 118         struct ldlm_res_id res_id = { .name = {0} };
 119         struct obd_device *obddev;
 120         ENTRY;
 121
 122         if (!de->d_inode)
 123                RETURN(0);
 124
 125         obddev = class_conn2obd(&sbi->ll_mdc_conn);
 126         res_id.name[0] = de->d_inode->i_ino;
 127         res_id.name[1] = de->d_inode->i_generation;
 128
 129         CDEBUG(D_INFO, "trying to match res "LPU64"\n", res_id.name[0]);
 130
 131         if (ldlm_lock_match(obddev->obd_namespace, LDLM_FL_BLOCK_GRANTED,
 132                             &res_id, LDLM_PLAIN, NULL, 0, LCK_PR, &lockh)) {
 133                 ldlm_lock_decref(&lockh, LCK_PR);
 134                 RETURN(1);
 135         }
 136
 137         if (ldlm_lock_match(obddev->obd_namespace, LDLM_FL_BLOCK_GRANTED,
 138                             &res_id, LDLM_PLAIN, NULL, 0, LCK_PW, &lockh)) {
 139                 ldlm_lock_decref(&lockh, LCK_PW);
 140                 RETURN(1);
 141         }
 142         RETURN(0);
 143 }
 144
 145 int ll_revalidate2(struct dentry *de, int flags, struct lookup_intent *it)
 146 {
 147         int rc;
 148         ENTRY;
 149
 150         /* We don't want to cache negative dentries, so return 0 immediately.
 151          * We believe that this is safe, that negative dentries cannot be
 152          * pinned by someone else */
 153         if (de->d_inode == NULL) {
 154                 CDEBUG(D_INODE, "negative dentry: ret 0 to force lookup2\n");
 155                 RETURN(0);
 156         }
 157
 158         if (it == NULL || it->it_op == IT_GETATTR) {
 159                 /* We could just return 1 immediately, but since we should only
 160                  * be called in revalidate2 if we already have a lock, let's
 161                  * verify that. */
 162                 struct inode *inode = de->d_inode;
 163                 struct ll_sb_info *sbi = ll_i2sbi(inode);
 164                 struct obd_device *obddev = class_conn2obd(&sbi->ll_mdc_conn);
 165                 struct ldlm_res_id res_id =
 166                         { .name = {inode->i_ino, (__u64)inode->i_generation} };
 167                 struct lustre_handle lockh;
 168                 rc = ldlm_lock_match(obddev->obd_namespace,
 169                                      LDLM_FL_BLOCK_GRANTED, &res_id,
 170                                      LDLM_PLAIN, NULL, 0, LCK_PR, &lockh);
 171                 if (rc) {
 172                         de->d_flags &= ~DCACHE_LUSTRE_INVALID;
 173                         if (it && it->it_op == IT_GETATTR) {
 174                                 memcpy(it->it_lock_handle, &lockh,
 175                                        sizeof(lockh));
 176                                 it->it_lock_mode = LCK_PR;
 177                                 LL_SAVE_INTENT(de, it);
 178                         } else {
 179                                 ldlm_lock_decref(&lockh, LCK_PR);
 180                         }
 181                         RETURN(1);
 182                 }
 183                 rc = ldlm_lock_match(obddev->obd_namespace,
 184                                      LDLM_FL_BLOCK_GRANTED, &res_id,
 185                                      LDLM_PLAIN, NULL, 0, LCK_PW, &lockh);
 186                 if (rc) {
 187                         de->d_flags &= ~DCACHE_LUSTRE_INVALID;
 188                         if (it && it->it_op == IT_GETATTR) {
 189                                 memcpy(it->it_lock_handle, &lockh,
 190                                        sizeof(lockh));
 191                                 it->it_lock_mode = LCK_PW;
 192                                 LL_SAVE_INTENT(de, it);
 193                         } else {
 194                                 ldlm_lock_decref(&lockh, LCK_PW);
 195                         }
 196                         RETURN(1);
 197                 }
 198                 if (S_ISDIR(de->d_inode->i_mode))
 199                         ll_invalidate_inode_pages(de->d_inode);
 200                 d_unhash_aliases(de->d_inode);
 201                 RETURN(0);
 202         }
 203
 204         rc = ll_intent_lock(de->d_parent->d_inode, &de, it, revalidate2_finish);
 205         if (rc < 0) {
 206                 CERROR("ll_intent_lock: rc %d : it->it_status %d\n", rc,
 207                        it->it_status);
 208                 RETURN(0);
 209         }
 210         /* unfortunately ll_intent_lock may cause a callback and revoke our
 211            dentry */
 212         spin_lock(&dcache_lock);
 213         list_del_init(&de->d_hash);
 214         spin_unlock(&dcache_lock);
 215         d_rehash(de);
 216
 217         RETURN(1);
 218 }
 219
 220 struct dentry_operations ll_d_ops = {
 221         .d_revalidate2 = ll_revalidate2,
 222         .d_intent_release = ll_intent_release,
 223         .d_release = ll_release,
 224 };